The Federal Capital territory Fire Service personnel were, however, on hand to contain the fire, which attracted a large crowd at the busy Area 10, Garki, in Abuja.
Efforts by a NAN correspondent to get information from officials of the service, on what led to the incident, were abortive.
A security officer, who pleaded anonymity, told NAN that the fire started at about 8:40 a.m.
An eyewitness, Mr Adamu Bala, said he drew the attention of the security officers guarding the building when he saw smoke coming from the back of the building.